One of the earliest methods used in Navajo jewelry design was stamping. Silversmiths use "dies," which are metal tools made from scraps of steel or iron with a pattern cut or filed into one end. Dies are used to stamp designs originally into silver and, more recently, into gold. Fine lines closely and uniformly stamped into silver or gold are known as chiselwork. Early Navajo silversmiths adapted stamping from techniques used by Mexican leatherworkers.